Trouble with Medication Timings - hl7-fhir

Question

Using the FHIR medication Schedule/Timing structure, what is the recommended way to represent these two frequencies: 1) For one hour every 21 days (e.g. for chemo infusions), and 2) Every 4-6 hours.
Thanks,

Answer 1

Well, after discussion within the FHIR project team, it appears that you'll have to use extensions for the moment, and that this will be addressed in R2 of FHIR.

Answer 2

This example may help:
http://hl7.org/fhir/2016Sep/medicationorder0317.json.html
excerpt
....
"dosageInstruction": [
{
"text": "Rapid daily-dose escalation, until tolerated, from 3 mg/d, and then 10 mg/d, to the recommended maintenance dose of 30 mg IV over 120 min, 3 times per wk on alternate days for up to 12 wk",
"additionalInstructions": [
{
"text": "Rapidly increase dose until tolerated"
},
{
"text": "Administer on alternate days"
}
],
"timing": {
"repeat": {
"duration": 12,
"durationUnit": "wk",
"frequency": 3,
"period": 1,
"periodUnit": "wk"
}
},
"route": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "47625008",
"display": "Intravenous route (qualifier value)"
}
]
},
"method": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "422145002",
"display": "Inject - dosing instruction imperative (qualifier value)"
}
]
},
"doseQuantity": {
"value": 3,
"unit": "mg",
"system": "http://loinc.org",
"code": "mg"
}
},
{
"text": "Rapid daily-dose escalation, until tolerated, from 3 mg/d, and then 10 mg/d, to the recommended maintenance dose of 30 mg IV over 120 min, 3 times per wk on alternate days for up to 12 wk",
"additionalInstructions": [
{
"text": "Rapidly increase dose until tolerated"
},
{
"text": "Administer on alternate days"
}
],
"timing": {
"repeat": {
"duration": 12,
"durationUnit": "wk",
"frequency": 3,
"period": 1,
"periodUnit": "wk"
}
},
"route": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "47625008",
"display": "Intravenous route (qualifier value)"
}
]
},
"method": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "422145002",
"display": "Inject - dosing instruction imperative (qualifier value)"
}
]
},
"doseQuantity": {
"value": 10,
"unit": "mg",
"system": "http://loinc.org",
"code": "mg"
}
},
{
"text": "Rapid daily-dose escalation, until tolerated, from 3 mg/d, and then 10 mg/d, to the recommended maintenance dose of 30 mg IV over 120 min, 3 times per wk on alternate days for up to 12 wk",
"additionalInstructions": [
{
"text": "Rapidly increase dose until tolerated"
},
{
"text": "Administer on alternate days"
}
],
"timing": {
"repeat": {
"duration": 12,
"durationUnit": "wk",
"frequency": 3,
"period": 1,
"periodUnit": "wk"
}
},
"route": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "47625008",
"display": "Intravenous route (qualifier value)"
}
]
},
"method": {
"coding": [
{
"system": "http://snomed.info/sct",
"code": "422145002",
"display": "Inject - dosing instruction imperative (qualifier value)"
}
]
},
"doseQuantity": {
"value": 30,
"unit": "mg",
"system": "http://loinc.org",
"code": "mg"
}
}
]